Continuous preparation of polyurethanes or polyureas

Abstract

Associative thickeners, and more particularly to associative thickeners of the HEUR type, may be used in aqueous formulations. In particular, a method for continuous preparation of HEUR-type associative thickeners may include reactive extrusion. These products are suitable to be used in aqueous formulations. Such a method may include: continuously preparing a hydrophilic polymer (P) by a reactive extrusion of precursors including a water-soluble polyalkylene glycol (A) and a product (B); and mixing the hydrophilic polymer (P) in a medium including a solvent. The water-soluble polyalkylene glycol (A) may include a polyethylene glycol, a polyethylene glycol-polypropylene glycol copolymer with at most 40% by weight of polypropylene glycol, and/or a polyethylene glycol-polybutylene glycol copolymer comprising at most 20% by weight of polybutylene glycol. The product (B) may include an associative group and an isocyanate group.

The invention claimed is: 
     
         1 . A method for preparing a thickening composition, the method comprising:
 continuously preparing a hydrophilic polymer (P), having a Mw in a range of from 60,000 to 500,000 g/mol, by a reactive extrusion of precursors comprising a water-soluble polyalkylene glycol (A), in at least 69.44 wt. % 80-wt. %, and a product (B), in a range of from 9.513 to 30.56 wt. %, relative to a total weight of the precursors; and   mixing the hydrophilic polymer (P) in a medium comprising a solvent,   wherein the water-soluble polyalkylene glycol (A) comprises a polyethylene glycol, a polyethylene glycol-polypropylene glycol copolymer comprising at most 40% by weight of polypropylene glycol, and/or a polyethylene glycol-polybutylene glycol copolymer comprising at most 20% by weight of polybutylene glycol,   wherein the water-soluble polyalkylene glycol (A) has a weight-average molecular mass (Mw) in a range of from 1,000 to 40,000 g/mol,   wherein the product (B) comprises an associative group and a monoisocyanate group,   wherein the product (B) comprises:   (b) a combination of a diisocyanate (B3) and a compound (B2) of formula (II):
   R′-(EO) n —(PO) m —(BO) p —X  (II),
 
   
       R′ being a straight, branched, or cyclic, saturated, unsaturated, or aromatic hydrocarbon group comprising from 6 to 40 carbon atoms, (EO) being an ethoxylene group, (PO) being a propoxylene group, (BO) being a butoxylene group, n, m, and p independently being a real number in a range of from 0 to 150, a sum of n, m, and p being a real number in a range of from 1 to 150, and X being a chemical group carrying a labile hydrogen suitable to react with an isocyanate group to form the monoisocyanate in the reactive extrusion; and/or
 (c) a product resulting from a prior condensation of the diisocyanate (B3) and the compound (B2) of formula (II). 
 
     
     
         2 . The method of  claim 1 , wherein the reactive extrusion is conducted in an extruder having a length/diameter ratio of greater than or equal to 20. 
     
     
         3 . The method of  claim 1 , wherein the product (B) comprises the combination (b), and
 wherein X in the compound (B2) is an alcohol group.   
     
     
         4 . The method of  claim 1 ,
 wherein the diisocyanate (B3) comprises 1,4-butane diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, isophorone diisocyanate, 1,3- and 1,4-cyclohexane diisocyanate, methylene bis(4-cyclohexylisocyanate), 2,6-toluene diisocyanate, 2,4-toluene diisocyanate, 2,2′-diphenylmethylene diisocyanate, 4,4′-diphenylmethylene diisocyanate, 2,4′-diphenylmethylene diisocyanate, 4,4′-dibenzyl diisocyanate, 2,4′-dibenzyl diisocyanate, m-xylylene diisocyanate, 1-methyl-2,4-diisocyanatocyclohexane, a combination of 1-methyl-2,4-diisocyanatocyclohexane with 1-methyl-2,6-diisocyanatocyclohexane, tetramethylxylene diisocyanate (TMXDI), and/or hexane trimethyl-1,6-diisocyanate.   
     
     
         5 . The method of  claim 1 , wherein the precursors in the reactive extrusion further comprise a cross-linking compound (C) in a range of from greater than 0 to 10 wt. %. 
     
     
         6 . The method of  claim 1 , wherein the reactive extrusion is carried out in the presence of a catalyst. 
     
     
         7 . The method of  claim 1 , wherein the product (B) is present in the precursors in a range of from 13.333 to 30.56 wt. %. 
     
     
         8 . The method of  claim 1 , wherein the solvent comprises water and/or an organic solvent. 
     
     
         9 . The method of  claim 1 , wherein the mixing comprises mixing the hydrophilic polymer (P) in the medium, the medium further comprising an amphiphilic compound, a polysaccharide derivative, a hydrotropic compound, an antifoaming agent, and/or a biocide agent. 
     
     
         10 . The method of  claim 1 , wherein the hydrophilic polymer (P) has a Mw in a range of from more than 150,000 to 500,000 g/mol, and
 wherein the water-soluble polyalkylene glycol (A) has a weight-average molecular mass (Mw) in a range of from 3,000 to 20,000 g/mol.   
     
     
         11 . The method of  claim 1 , wherein the water-soluble polyalkylene glycol (A) has a weight-average molecular mass (Mw) in a range of from 4,000 to 15,000 g/mol. 
     
     
         12 . The method of  claim 1 , wherein the product (B) comprises the combination (b), and
 wherein X in the compound (B2) is an amine group.   
     
     
         13 . The method of  claim 1 , wherein the precursors in the reactive extrusion further comprise a polyol, polyamine, and/or a polyisocyanate comprising more than two isocyanate groups. 
     
     
         14 . The method of  claim 6 , wherein the catalyst comprises acetic acid. 
     
     
         15 . The method of  claim 6 , wherein the catalyst comprises an amine. 
     
     
         16 . The method of  claim 6 , wherein the catalyst comprises Al, Bi, Sn, Hg, Pb, Mn, Zn, Zr, and/or Ti. 
     
     
         17 . The method of  claim 1 , wherein the solvent comprises water. 
     
     
         18 . The method of  claim 1 , wherein the solvent is mainly water. 
     
     
         19 . A method for preparing a thickening composition, the method comprising:
 continuously preparing a hydrophilic polymer (P), having a Mw in a range of from 60,000 to 500,000 g/mol, by a reactive extrusion of precursors comprising a water-soluble polyalkylene glycol (A), in at least 69.44 wt. %, and a product (B), in a range of from 9.513 to 30.56 wt. %, relative to a total weight of the precursors; and   mixing the hydrophilic polymer (P) in a medium comprising a solvent,   wherein the water-soluble polyalkylene glycol (A) comprises a polyethylene glycol, a polyethylene glycol-polypropylene glycol copolymer comprising at most 40% by weight of polypropylene glycol, and/or a polyethylene glycol-polybutylene glycol copolymer comprising at most 20% by weight of polybutylene glycol,   wherein the water-soluble polyalkylene glycol (A) has a weight-average molecular mass (Mw) in a range of from 1,000 to 40,000 g/mol,   wherein the product (B) comprises an associative group and a monoisocyanate group,   wherein the product (B) comprises:   (b) a combination of a diisocyanate (B3) and a compound (B2) of formula (II):
   R′—(BO) n —(PO) m —(BO) p —X  (II),
 
   
       R′ being a straight, branched, or cyclic, saturated, unsaturated, or aromatic hydrocarbon group comprising from 6 to 40 carbon atoms, (EO) being an ethoxylene group, (PO) being a propoxylene group, (BO) being a butoxylene group, n, m, and p independently being a real number in a range of from 0 to 150, a sum of n, m, and p being a real number in a range of from 0 to 150, and X being an amine group; and/or
 (c) a product resulting from a prior condensation of the diisocyanate (B3) and the compound (B2) of formula (II). 
 
     
     
         20 . A method for preparing a thickening composition, the method comprising:
 continuously preparing a hydrophilic polymer (P), having a Mw in a range of from 60,000 to 500,000 g/mol, by a reactive extrusion of precursors comprising a water-soluble polyalkylene glycol (A), in at least 55 wt. %, and a product (B), in a range of from 9.513 to 45 wt. %, relative to a total weight of the precursors; and   mixing the hydrophilic polymer (P) in a medium comprising a solvent and further comprising,   wherein the water-soluble polyalkylene glycol (A) comprises a polyethylene glycol, a polyethylene glycol-polypropylene glycol copolymer comprising at most 40% by weight of polypropylene glycol, and/or a polyethylene glycol-polybutylene glycol copolymer comprising at most 20% by weight of polybutylene glycol,   wherein the water-soluble polyalkylene glycol (A) comprises a polyethylene glycol,   wherein the water-soluble polyalkylene glycol (A) has a weight-average molecular mass (Mw) in a range of from 1,000 to 40,000 g/mol,   wherein the product (B) comprises an associative group and a monoisocyanate group,   wherein the product (B) comprises:   (b) a combination of a diisocyanate (B3) and a compound (B2) of formula (II):
   R″-(EO) n —(PO) m —X  (II),
 
   
       R″ being a hydrocarbon group of formula C 15 H 31-x  where x is 0, 2, 4, or 6, (EO) being an ethoxylene group, (PO) being a propoxylene group, n, m, and p independently being a real number in a range of from 0 to 150, a sum of n, m, and p being a real number in a range of from 4 to 150, and X being a chemical group carrying a labile hydrogen suitable to react with an isocyanate group to form the monoisocyanate in the reactive extrusion; and/or
 (c) a product resulting from a prior condensation of the diisocyanate (B3) and the compound (B2) of formula (II).